Improvement in boiler-furnaces



S. A. FORD.

Boiler-Furnaces.

Patented August 19, 1873.

UNITED STATES SAMUEL A. FORD, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN B O ILER-FURNACES.

Specification forming part of Letters Patent No. [$1,870, dated August19, 1873 application filed May 23, 1873.

To all whom it may concern:

Be it known that I, SAMUEL A. FORD, of the city of Chicago, in thecounty of Cook and State of Illinois, have invented a new and usefulImprovement in Boiler-Furnaces, of which the following is aspecification:

My invention is especially adapted for use in connection withsteam-boilers and heatingfurnaces, but I shall more particularlydescribe its application to steam-boilers, it being observed that in thecase of heating-furnaces the top of the wall of the furnace correspondsto the bottom of the boiler, as herein referred to. The object of myinvention is to provide a cheap and effective method of promoting thecombustion of the volatile hydrocarbon and other gases which, in passingoff as smoke, occasion .great loss of heat and consequent waste of fuel.The principle involved is that well-known principle of combining withthe flame of burning fuel a suita ble amount of atmospheric air at thetime and place where the greatest expansion of the gases is had, andhence the highest temperature obtained.

To accomplish this purpose I construct in the following manner a chamberfor heating and distributing air: The space immediately in the rear ofthe bridge-wall in general use is bricked up as far as may be desirable,the top line of this brick-work having a sharp deflection beginning atthe level of the bridge wall. Above the bridge-wall and this brickwork,and resting upon the same, there is constructed an arched chamber orseries of chambers at the front end, setting close against the bottom ofthe boiler, but as extended deflected, so as to be parallel with thedeflection of the brick-work below. At the rear end of the archedchamber or chambers the brickwork is carried up close against theboiler, thus forming an intermediate space or chamber between the top ofthe arch or arches and the bottom of the boiler. The space between thewalls sustaining the arches and the brickwork of the boiler setting orspace between the several arches, as the case may be, form a part of theair-chamber, and by means of perforations the heated air is minutelymingled with the gases while passing through the arched chamber orchambers constructed as described. The deflection referred to leaves aslarge a hot-air space between the boiler and the arched passage as' maybe desired, and, being narrowed at the front end where the heat firststrikes it, the temperature of the air within it is equalized as nearlyas possible, thus preventing any chilling of the gases while passingthrough the chambers, and being mingled with the air admitted throughthe perforations in the arch or arches and the walls sustaining thesame. The object of constructing the hot-air space or chamber above theline of the bridge-wall, and the rear of the same, and of giving it asuitable deflection, or as great a deflection as may be had withoutobstructing the draft, is to overcome the difflculty hithertoexperienced in perfectly burning the smoke, arising from the tendency ofthe lighter gases to hug close to the bottom of the boiler, and thusprevent a proper combination with atmospheric air, as heretoforeadmitted, requisite to perfect combustion. In some instances, however,in using fuel where a large amount of air is required, Iconstruct anair-chamber in the brick-work immediately under the one here described,and connected with the same by means of the spaces referred to betweenthe walls of the boiler-setting and the walls of the arches, or betweenthe walls of the several arches. But where this is done the bottom ofeach arched passage is perforated as well as the top, thus completelysurrounding the current of flame and gases with the appliance fordistributing and combining the air. The lower chamber is, however,rarely required where the upper one is constructed of suitable lengthand capacity, that in any event being far more effective for the purposedesired.

The arched passage or passages may be constructed of any materialcapable of resisting a very high temperature. The object of arching thetop of the passages herein described is simply to give strength anddurability, but when the space is not too great they may be made flat,that form answering the purpose equally well. Into the hot-air spaceunderneath the boiler and over the arched passages formed as theredescribed, air is admitted in any convenient manner, but the. mode Ihave shown in the accompanying drawings I have found most satisfactory,as

thereby the air becomes highly heated before entering the hot-airchamber.

In order to control the supply of air, thereby meeting the variabledemands of different stages of combustion, as also to increase the draftwhere, from any cause, defective, a small steam-pipe is conducted fromthe dome of the boiler to the hot-air chamber in any convenient manner,but one or the other of the two plans of introducing this steam-pipeshown in the drawings I have found suitable to almost all furnaces. Thepipe is extended across the hot-air chamber at right angles with theboiler, and by means of small perforations in the steam-pipe the supplyof steam is equally distributed, and the supply of air thereby easilycontrolled. When it is inconvenient to use steam any ordinary blast willanswer the same purpose. A steam-pipe is also taken from the dome to thefront of the boiler and admitted either into the tire-box above thefurnacedoor and hence above the fuel or underneath the same, as may bemost convenient. In either case the same object is accomplished, viz.,to give an accelerated draft immediately after renewing the supply offuel, and in certain conditions of the atmosphere. An ordinary blast maybe substituted for steam here also, if more convenient.

In the accompanying drawings forming a part of this specification theoutline of an ordinary boiler with the best interior form of setting isshown, the better to illustrate the nature and application of myinvention.

Figure 1 is a vertical longitudinal section through lines L L. Fig. 2 isa vertical crosssection through lines K K.

A represents an ordinary boiler; B, parts of the brick-work incasin gthe same; 0, the hot'air chamber; D, the passages or chambers for flameand gases; E, the air-pipe leading to the hot-air chamber 0 F and 0,steam-pipes; G, globe valves to regulate the supply of steam; H,door-opening for cleaning out behind the bridge-wall, &c.; I, thefire-box; J, the bridge-wall.

What I claim, and desire to secure by Letters Patent, is

The hot-air chamber 0, and deflected perforated chamber D, incombination with the airpipes E, steam-pipes F and 0, arrangedsubstantially as specified and shown, and for the purpose set forth.

SAMUEL A. FORD.

Witnesses:

JOHN F. GoLLINs, J. G. KING.

